Magnesium Dosage Calculator
Calculate your personalised magnesium dose based on Australian guidelines. NHMRC RDI: 420 mg/day (male) / 320 mg/day (female).
Calculate Your Dose
Important Warnings
- People with kidney disease should consult a doctor before supplementing.
- High doses can cause diarrhea — start low and increase gradually.
- May interact with antibiotics, bisphosphonates, and diuretics.
Tips for Better Absorption
- Take glycinate form 30–60 min before bed for sleep.
- Avoid taking with high-dose zinc or calcium (they compete for absorption).
- Food sources: pumpkin seeds, almonds, spinach, dark chocolate.
Frequently Asked Questions
How much magnesium should I take for sleep?
For sleep, take 200–400 mg of magnesium glycinate 30–60 minutes before bed. Start at 200 mg and increase if needed. Most people notice improved sleep onset within 1–2 weeks.
What is the best form of magnesium to take?
Magnesium glycinate is best for sleep and anxiety (high absorption, gentle on stomach). Magnesium citrate is good for constipation. Magnesium oxide has very low absorption (~4%) and is the least effective form.
Can you take too much magnesium?
The Australian upper limit for supplemental magnesium is 350 mg/day. Exceeding this can cause diarrhea and stomach cramps. Magnesium from food does not count toward this limit.
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This calculator provides general guidance based on Australian NHMRC guidelines and published clinical research. It is not medical advice. Individual needs vary. Always consult a healthcare professional before starting any supplement, especially if you are pregnant, breastfeeding, taking medications, or have a medical condition.